More specifically, the present invention relates to a method and device for producing a rigid container, comprising two end walls and a lateral wall, from a flat blank comprising two flat first portions, each of which comprises a panel defining a relative said end wall of the container, and a drawn rim integral with the panel and extending, squarely with respect to the panel, along at least one portion of an outer edge of the panel; and three flat second portions alternating with said two panels; each said panel being folded squarely with respect to the flat second portions adjacent to it, and said second portions being wrapped about and onto said rims to form said lateral wall.
Though suitable for producing any type of container, the present invention is particularly advantageous for use in the tobacco industry, for producing, on a packing machine, containers defined by hinged-lid cigarette packets, and particularly hinged-lid packets having a substantially oval cross section, as described and illustrated in the Applicant's International Patent Application N. WO-A-03/080474, to which the following description refers purely by way of example.
Particularly when working with high-speed packing machines operating at an output speed in the region of 7–10 packets a second, producing packets of the above type poses various difficulties, due to possible inward flexing of the rims when said second portions are wrapped about and onto the rims of said first portions, thus resulting, in view of the relatively small transverse dimensions of the rims, in failure to close the packets.